Method and apparatus for stack cutting metal sheets and plates



Jan. 28, 1964 D. c. CAMPBELL 3,119,724

METHOD AND APPARATUS FOR STACK CUTTING METAL SHEETS AND PLATES Filed Oct. 19, 1961 2 Sheets-Sheet 1 INVENTOR. .051. 70M 6. CAMPBELL Jan. 28, 1964 D. c. CAMPBELL 3,119,724

METHOD AND APPARATUS FOR STACK CUTTING METAL SHEETS AND PLATES Filed Oct. 19, 1961 2. Sheets-Sheet 2 INVENTOR. DEA ro/v (I, 6,044 55 Mm/m/ United States Patent 3,119,724 METHOD AND APPARATUS FOR STACK CUTTING METAL SHEETS AND PLATES Delton C. Campbell, Fullerton, Calif, assignor to Challenge-Cook Bros, Los Angeles, Calif a corporation of California Filed Oct. 19, 1961, Ser. No. 146,235 a claims. or. 148--9) This invention relates to a method of simultaneously producing a plurality of forms cut from metal sheets or plates, and the apparatus for performing said method. More particularly, it relates to a method and apparatus for simultaneously producing such forms from a stack of overlying sheets or plates.

There are many devices and methods, many of them quite complicated, for automatically cutting or burning sheet metal and plate wherein the torch follows a template to produce a form from a single sheet or plate, but until the present invention no satisfactory method or device has been oifered which will quickly and easily produce a plurality of forms from a plurality of sheets or plates stacked one upon the other, with a single cutting.

Stack burning, when attempted, has not been fully satisfactory because it has been diificult to retain the sheets or plates tightly compressed to each other at the line of burning during the cutting process, so as to permit an accurately aligned cut on all sheets or plates simultaneously and prevent blow-out between sheets or plates, which occurs if they are not tightly compressed.

It is therefore an object of the present invention to provide a method and apparatus for cutting through a stack of metal sheets or plates so as to simultaneously produce a plurality of forms of the same configuration and of exact tolerances.

It is another object of the invention to provide such a method and apparatus wherein said sheets or plates are effectively compressed together during the cutting operation.

It is still another object to provide an apparatus for performing the method of the invention which is uncomplicated and easy and inexpensive to construct, install and operate.

It is a further object to provide a method of stack burning which is quick and easy to perform, but which simultaneously produces a plurality of accurately cut products.

With these and other objects in view, the invention consists of the construction, arrangement and combination of the various parts of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of the device of the present invention.

FIGURE 2 is an end elevational view of the device.

FIGURE 3 is a view taken on the line 33 of FIG- URE 2.

FIGURE 4 is a view taken on the line 44 of FIG- URE 2.

FIGURE 5 is a detailed side elevational view of the driving means of the device of the present invention.

FIGURE 6 is a perspective view of a stack of forms processed by the method and apparatus of the present invention.

A bench 10, which may be supported on legs 11, has rails 12 mounted adjacent its longitudinal edges 13, said rails 12 extending over substantially the entire length of bench 10.

Rollers 20 are mounted on said rails 12 and support a carriage 21. Carriage 21 comprises side members 22 3,119,724 Patented Jan. 28, 1964 disposed externally of edges 13 of bench 10, on which said side members 22 rollers 20 are rotatably mounted; a cross-rail 23, which is disposed in spaced transverse relationship to bench 10; and support members 24, which are mounted on side members 22 and support cross-rail 23.

A carriage 30 has a body frame member 31 on which are rotatably mounted rollers 32. Rollers 32 are disposed on cross-rail 23.

Mounted on carriage 30 is a fluid cylinder assembly 40. Depending from cylinder assembly is a hollow shaft 41, in which a piston rod 42 is disposed. A piston 43 is mounted on the lower end of piston rod 42. A

collar 44 is mounted on shaft 41, and a rotating collar 45 is also mounted on shaft 41, below collar 44.

A template is mounted in horizontal position on collar 44, preferably at a generally centrally located point on template 50. Mounting of template 50 on collar 44 may be by any suitable means, the mounting illustrated in the drawings being by means of a centrally bored plate 51, collar 44 being disposed in the bore of plate 51, and plate 51 being secured to template 50, as by fasteners 52, said plate 51 being disposed so as to cover a suitable opening in template 50.

Articulated support arms and 61 are mounted on rotating collar 45 and extend outwardly therefrom. They support a variable speed motor 62 which may be equipped with a rheostat 63. Projecting upwardly from motor 62 is a drive shaft 64, disposed so that said drive shaft 64 will make contact with the edges of template 50. The upper end 65 of drive shaft 64 is magnetized so as to be attracted to and maintained in position in contact with the edges of template 50.

In order to provide stability, in lieu of a single pair of articulate arms, another pair of articulate arms and 71 may be similarly mounted on collar 45, but spaced apart from and below arms 60 and 61, said four articulate arms being joined by transverse rods 72 and 73.

Arm 71 supports a cutting torch 80, which is substantially aligned wtih drive shaft 64. The operating head 81 of torch is suspended below arm 71.

A stack of sheets or plates is disposed on bench 10 between edges 13, said stack 90 being straddled by carriage 21.

A hold-down assembly member 100, best illustrated in FIGURE 4 of the drawings, is placed on top of stack 90, in position under cross-rail 23 of carriage 21. Holddown assembly member 191) may be of any suitable configuration, but it has been found to be preferably, in order to insure firm downward pressure closely adjacent to a proposed cutting line a, while still leaving space for the unobstructed movement of head 81 of torch S0, to provide a hold-down assembly member which is of a configuration substantially similar to the configuration of template 59, but of reduced size. Hold-down assembly 100, as illustrated in FIGURE 4, has edge members 101, 1112, 103 and 104, longitudinal cross-brace 1115, intersecting cross-brace 1136 (which intersects cross-brace 105 at approximately the middle of cross-brace 105 to form a seat for piston 43, as hereinafter mentioned), and oblique cross-braces 167 and 198, but the hold-down assembly herein described is merely illustrative, and any other hold-down assembly may be used, provided it is sufficiently strong to receive fluid pressures of sufficient intensity to permit it to firmly compress the sheets or plates in stack 90 closely adjacent the proposed cutting line and and prevent blow-out between the sheets or plates during the burning-cutting operation hereinafter described. It will also be recognized that if desired a solid hold-down member may be used.

In operation, a stack 91) of sheets or plates having been disposed on bench 10, carriage 21 is moved along rails 12 until carriage 21 is in straddling position over stack 90 at a place where form cutting is to be made. Carriage is then moved along cross-rail 23 until carriage 36 is disposed over the approximate center of the proposed form to be cut. Template 59 is then aligned, and holddown assembly 109 is placed on stack 90 and aligned with template so that hold-down assembly 109 will be disposed on stack 90 closely adjacent to, but spaced apart from, proposed cutting line ldila.

Fluid pressure is then exerted in fluid cylinder assembly 49 to impel piston rod 4-2 and piston 4-3 mounted thereon toward hold-down assembly 100, such fluid pressure being continued until piston 43 is firmly seated on hold-down assembly 19%), said fluid pressure being continued during the entire cutting operation so that hold-down is firm and complete.

By manipulation of arms 60, 61, 70 and 71, upper end of drive shaft 64 of motor 62 is brought into contact with the edge of template 50. Contact of end 65 with template 5% is maintained by magnetic attraction.

On manipulation of arms 60, 61, and '71 to bring end 65 of drive shaft 64 into contact with template 5t torch 8% supported by said arms 69, 61, 70 and 71 will be disposed over proposed cutting line 166a. Operating head 81 of torch is then brought into contact, or close proximity to stack in accurate alignment with proposed cutting line 1613a.

Rheostat 63 of motor 62 is adjusted, dependent on the hardness and thickness of the sheets or plates in stack 90 which are to be cut.

When motor 62 is energized, magnetized end 65 of shaft 64 will proceed to move at predetermined speed around the edges of template 5%), moving arms 60, 61, 70 and 71, which in turn will move operating head 81 of torch 89 in a path along cutting line 108a. Torch 80 will cut through the entire stack 90, and the path of cut will correspond to the configuration of template 50. During the entire cutting operation the sheets or plates in stack 90 will be firmly held against buckling, expansion, or other movement by the hold-down action of hold-down assembly 160.

When end 65 of shaft 64 has moved around the entire edge surfaces of template 5% a corresponding full cut will have been made by torch 80. Motor 62 is then deenergized, and fluid pressure is relieved in fluid cylinder assembly 40. Hold-down assembly is then removed from stack 90. The resulting stack of accurately cut forms thus produced, such as stack 260 illustrated in FIG- URE 6 of the drawings, may then be removed from bench 10, and if desired, by movement of carriage 21 to another location along rails 12, the cutting operation may be repeated at another part of stack 90.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent structures and methods.

What is claimed is:

l. A method of simultaneously producing a plurality of forms cut from metal sheets or plates which comprises the steps of: forming a flat stack of pieces of the material to be cut; suspending a template over said stack; applying to said stack hold-down means of a configuration similar to but smaller than said template; aligning the hold-down means closely adjacent to a cutting path; aligning a cutting torch with said template; applying automatic template following means to the torch, said means automatically following the template so as to allow the torch to cut in a pattern corresponding to the peripheral contour of the template; energizing said torch; and driving said torch along a cutting path in close proximity to the outside edges of said hold-down means so as to cut through said stack in a pattern determined by said template.

2. The method of claim 1, including the step of applying pressure to said hold-down means during the cutting operation so as to prevent movement of pieces in said stack relative to each other.

3. The method of claim 2, wherein said pressure is fluid pressure.

4. Apparatus for simultaneously producing a plurality of forms cut from metal sheets or plates which comprises: a bench for supporting a fiat stack of pieces of material to be cut; rails mounted longitudinally adjacent the edges of said bench; a first carriage movably mounted on said rails and straddling said bench and said stack; a second carriage supported by said first carriage in suspended position over said bench and movable on said first carriage transversely to said bench; a fluid cylinder assembly mounted on said second carriage; a hollow shaft mounted on and depending from said fluid cylinder assembly; a piston rod disposed in said fiuid cylinder assembly and in said hollow shaft, and protruding from said hollow shaft; a piston mounted on said piston rod externally of said hollow shaft; a hold-down member seated on said stack and disposed so as to receive said piston when fluid pressure is exerted in said fluid cylinder assembly, said hold-down member being of a configuration substantially the same as, but slightly smaller than, the configuration of the template, and said hold-down means being disposed in vertical alignment with the template; a template mounted on said hollow shaft in spaced, substantially parallel relationship to said stack and in vertical alignment with said hold-down member; a cutting torch; means rotatably mounted on said shaft for supporting said torch in a pattern of travel determined by the periphery of said template; a motor mounted on the torch; and a projecting, magnetized drive shaft on the motor aligned with said torch and in contact with the periphery of the template so as to guide the torch in the pattern of travel determined by said periphery.

5. Apparatus for simultaneously producing a plurality of forms cut from metal sheets or plates which comprises: a bench for supporting a flat stack of pieces of material to be cut; a template suspended over said stack; holddown means for compressing said pieces together, said hold-down means being of a configuration substantially the same as, but slightly smaller than, the configuration of the template, and said hold-down means being disposed in vertical alignment with the template; a cutting torch aligned with said template and disposed so as to cut through said stack in a pattern determined by said template and on a line in close proximity to said hold-down means; and a magnetized drive shaft mounted on the cutting torch and disposed so as to be attracted to and maintained in traveling position in contact with the edges of the template.

6. Apparatus for simultaneously producing a plurality of forms cut from metal sheets or plates, which comprises: a bench for supporting a flat stack of pieces of material to be cut; a first carriage supported by said bench, movable longitudinally thereon, and straddling said bench and said stack; a second carriage supported by said first car riage, suspended above said bench, and movable transversely in relation to said bench; a downwardly directed hollow shaft mounted on said second carriage; a template mounted on said shaft in substantially parallel relationship to said stack; a cutting torch; means rotatably mounted on said shaft for supporting and guiding said torch in a pattern of travel determined by the periphery of said template; a hold-down member disposed on said stack, said hold-down member being of a configuration substantially the same as, but slightly smaller than, the configuration of the template, and said hold-down member being disposed in vertical alignment with the template; and means associated with the hollow shaft for exerting hold-down pressure on the hold-down member.

7. Apparatus as defined in claim 6, wherein the means for guiding said torch comprises: a motor; and a project- 5 6 ing drive shaft on said motor in magnetized contact With References Cited in the file of this patent thfi periphery of Sald template.

8. Apparatus as defined in claim 6, wherein said means 1 for exerting hold-down pressure on said hold-down mem- 2,178,938 Ohmstede 1939 her comprises: a fluid cylinder assembly; a piston rod 5 OTH RE RENC S assomated with said fluid cylinder assembly and disposed Oxygen Cutting, by Slottman and Roper, first ed. 1951 in and extending from said hollow shaft; and a piston mounted on said piston rod and seated on said hold-down gg g g Book New York member. 

1. A METHOD OF SIMULATANEOUSLY PRODUCING A PLURALITY OF FORMS CUT FROM METAL SHEETS OR PLATES WHICH COMPRISES THE STEPS OF: FORMING A FLAT STACK OF PIECES OF THE MATERIAL TO BE CUT; SUSPENDING A TEMPLATE OVER SAID STACK; APPLYING TO SAID STACK HOLD-DOWN MEANS OF A CONFIGURATION SIMILAR TO BUT SMALLER THAN SAID TEMPLATE; ALIGNING THE HOLD-DOWN MEANS CLOSELY ADJACENT TO A CUTTING PATH; ALIGNING A CUTTING TORCH WITH SAID TEMPLATE; APPLYING AUTOMATIC TEMPLATE FOLLOWING MEANS TO THE TORCH, SAID MEANS AUTOMATICALLY FOLLOWING THE TEMPLATE SO AS TO ALLOW THE TORCH TO CUT IN A PATTERN CORRESPONDING TO THE PERIPHERAL COUNTOUR OF THE TEMPLATE; ENERGIZING SAID TORCH; AND DRIVING SAID TORCH ALONG A CUTTING PATH IN CLOSE PROXIMITY TO THE OUTSIDE EDGES OF SAID HOLD-DOWN MEANS SO AS TO CUT THROUGH SAID STACK IN A PATTERN DETERMINED BY SAID TEMPLATE. 